In the present study, we studied the inhibitory effects of chelidonine and rutaecarpin on porcine pancreatic a-amylase （PPA） catalyzed hydrolysis using 2-chloro-4-nitrophenyl-4-O-β-D-galactopyranosylmaltoside （Gal...In the present study, we studied the inhibitory effects of chelidonine and rutaecarpin on porcine pancreatic a-amylase （PPA） catalyzed hydrolysis using 2-chloro-4-nitrophenyl-4-O-β-D-galactopyranosylmaltoside （Gal-G2-α-CNP）. We, for the first time, provided kinetic report and detailed inhibitory effects of both compounds on PPA. Lineweaver-Burk plot revealed that the inhibition was a mixed-noncompetitive type, and only one molecule of inhibitor bound to the enzyme or to the enzyme-substrate complex. Kinetic constants calculated from secondary plots were in millimole range. Dissociation constants of enzyme-inhibitor complex （KEI） were 0.9 mM and 3.5 mM, respectively. Moreover, dissociation constants of enzyme-inhibitor-substrate complex （KESI） were 0.04 mM and 0.31 mM, respectively. These data indicated that the inhibition was more inclined to competitive to Gal-G2-α-CNP hydrolysis. Further molecular docking study manifested that hydrogen bonding formed between acarbose and aspartic acid （Asp300）, histidine （His305） and glycine （Gly3-6）, while hydrogen bonding was observed between chelidonine and glutamic acid （Glu233）, lysine （Lys200） and His305. In addition, rutaecarpine had only one hydrogen bond with Lys200. Our data indicated that chelidonine and rutaecarpine were two promising drug candidates, and chelidonine possessed stronger inhibitory effect compared with rutaecarpine.展开更多
In order to systematically investigate the chemical constituents of Citri Reticulatae Folium （leaves of ＇Fuju＇）, an analytical method that included high-performance liquid chromatography, diode array detection, el...In order to systematically investigate the chemical constituents of Citri Reticulatae Folium （leaves of ＇Fuju＇）, an analytical method that included high-performance liquid chromatography, diode array detection, electrospray ionization, and ion-trap time-of-flight mass spectrometry （HPLC-DAD-ESI-MSn） was used to separate and identify the individual chemical components of Citri Reticulatae Folium. As a result, 96 compounds were tentatively identified in this study： including 31 phenolic acids, 4 flavonoid aglycones, 6 flavonoid mono-O-glycosides, 10 flavonoid-O-diglycosides, 5 flavonoid mono-C-glycosides, 5 flavonoid di-C-glycosides, 6 flavonoid O,C-glycosides, 5 （3-hydroxy-3-methylglutaryl） glycosyl flavonoids, 1 flavan-3-ol, and 2 alkaloids. In addition, 21 polymethoxy flavonoids （PMFs） were identified in this paper. Among these compounds, 52 compounds, which were previously found in other Citrus plants, have been identified for the first time in Citri Reticulatae Folium. 15 compounds have not been previously found in the Citrus genus were identified. Moreover, 9 potentially new compounds have also been detected in this paper. This is the first report of the full characterization of chemical components of Citri Reticulatae Folium （leaves of＇Fuju＇） by HPLC-DAD-ESI-MSn.展开更多
The interactions of chlorogenic acid （CA）, neochlorogenic acid （NCA） and cryptochlorogenic acid （CCA） with lysozyme （LYSO） were investigated in physiological buffer by fluorescence spectroscopy. The mechanism ...The interactions of chlorogenic acid （CA）, neochlorogenic acid （NCA） and cryptochlorogenic acid （CCA） with lysozyme （LYSO） were investigated in physiological buffer by fluorescence spectroscopy. The mechanism study indicated that CA, NCA and CCA could strongly quench the intrinsic fluorescence of LYSO through static quenching procedures with one binding site. Thermodynamic data show that the major force in the binding processes of CA to LYSO was hydrophobic interactions; for NCA, it was the hydrogen bonds and van der Waals forces, as for the CCA system, the mainly force is electrostatic force.展开更多
基金State Key Laboratory of Natural and Biomimetic Drugs 2013 Funded Project "Establishment and Application an Online Natural Medicines System with Efficient Separation,Structural Identification and Activity Detection"
文摘In the present study, we studied the inhibitory effects of chelidonine and rutaecarpin on porcine pancreatic a-amylase （PPA） catalyzed hydrolysis using 2-chloro-4-nitrophenyl-4-O-β-D-galactopyranosylmaltoside （Gal-G2-α-CNP）. We, for the first time, provided kinetic report and detailed inhibitory effects of both compounds on PPA. Lineweaver-Burk plot revealed that the inhibition was a mixed-noncompetitive type, and only one molecule of inhibitor bound to the enzyme or to the enzyme-substrate complex. Kinetic constants calculated from secondary plots were in millimole range. Dissociation constants of enzyme-inhibitor complex （KEI） were 0.9 mM and 3.5 mM, respectively. Moreover, dissociation constants of enzyme-inhibitor-substrate complex （KESI） were 0.04 mM and 0.31 mM, respectively. These data indicated that the inhibition was more inclined to competitive to Gal-G2-α-CNP hydrolysis. Further molecular docking study manifested that hydrogen bonding formed between acarbose and aspartic acid （Asp300）, histidine （His305） and glycine （Gly3-6）, while hydrogen bonding was observed between chelidonine and glutamic acid （Glu233）, lysine （Lys200） and His305. In addition, rutaecarpine had only one hydrogen bond with Lys200. Our data indicated that chelidonine and rutaecarpine were two promising drug candidates, and chelidonine possessed stronger inhibitory effect compared with rutaecarpine.
文摘In order to systematically investigate the chemical constituents of Citri Reticulatae Folium （leaves of ＇Fuju＇）, an analytical method that included high-performance liquid chromatography, diode array detection, electrospray ionization, and ion-trap time-of-flight mass spectrometry （HPLC-DAD-ESI-MSn） was used to separate and identify the individual chemical components of Citri Reticulatae Folium. As a result, 96 compounds were tentatively identified in this study： including 31 phenolic acids, 4 flavonoid aglycones, 6 flavonoid mono-O-glycosides, 10 flavonoid-O-diglycosides, 5 flavonoid mono-C-glycosides, 5 flavonoid di-C-glycosides, 6 flavonoid O,C-glycosides, 5 （3-hydroxy-3-methylglutaryl） glycosyl flavonoids, 1 flavan-3-ol, and 2 alkaloids. In addition, 21 polymethoxy flavonoids （PMFs） were identified in this paper. Among these compounds, 52 compounds, which were previously found in other Citrus plants, have been identified for the first time in Citri Reticulatae Folium. 15 compounds have not been previously found in the Citrus genus were identified. Moreover, 9 potentially new compounds have also been detected in this paper. This is the first report of the full characterization of chemical components of Citri Reticulatae Folium （leaves of＇Fuju＇） by HPLC-DAD-ESI-MSn.
文摘The interactions of chlorogenic acid （CA）, neochlorogenic acid （NCA） and cryptochlorogenic acid （CCA） with lysozyme （LYSO） were investigated in physiological buffer by fluorescence spectroscopy. The mechanism study indicated that CA, NCA and CCA could strongly quench the intrinsic fluorescence of LYSO through static quenching procedures with one binding site. Thermodynamic data show that the major force in the binding processes of CA to LYSO was hydrophobic interactions; for NCA, it was the hydrogen bonds and van der Waals forces, as for the CCA system, the mainly force is electrostatic force.
